The influencing of the immune response by a immune enhancement agent can decisively determine the course of the disease. This is particularly the case with malignant tumors, infections caused by fungi, viruses and parasites which cannot, or cannot adequately be given therapy, immuno-deficiency syndromes and by an immuno-suppression, e.g. in the case of foreign body transplants, autoimmune diseases or inflammatory diseases.
Cytokins are able to stimulate cells of the immune system in such a way as to act in the immune process in an immuno-activating or immuno-suppressing manner.
Despite the excellent perspectives with respect to the treatment of therapy resistant and infectious diseases, considerable problems are encountered during the administration or application of such cytokins.
The immuno-reaction provided by cytokins is difficult to control through the supply of exogenous cytokins. Only a rough immuno-response control is possible with the heretofore used systemic application processes (intravenous, intramuscular or subcutaneous cytokin administration). A further important disadvantage of the heretofore conventional systemic cytokin therapy is the extremely severe side effects, which lead to treatment only being possible with particularly good patients, who must in part be treated in intensive care units.
Interleukin-2, interferon and the tumor necrosis factor have been particularly well tested in this connection. However, other cytokins are in experimental use.
Systemic side effects such as fever, shivers, nausea, vomiting, diarrhea, life-threatening effects on the cardiovascular system such as heterotonia (varying blood pressure), dysrhythmia and the much feared capillary leakage syndrome, i.e. water retention due to a vascular sealing loss, are accompanying phenomena of systemic immuno-enhancement by cytokins. These are discussed in: Lotze, M. T., et al, "Clinical Effects and Toxicity of Interleukin-2 in Patients With Cancer" Cancer 58: 2764, 1986; Thompson, J. A., et al, "Recombinant Interleukin-2 Toxicity, Pharmacokinetics, and Immunomodulatory Effects in a Phase 1 Trial" Cancer Res. 47: 4202, 1987; West, W. H., et al, "Constant-Infusion Recombinant-Interleukin-2 in Adoptive Immunotherapy of Advanced Cancer" N.Engl.J.Med.: 898, 1987; Lotze, M. T., et al, "High-Dose Recombinant Interleukin-2 in the Treatment of Patients with Disseminated Cancer" J.A.M.A. 256: 3117, 1986; Rosenberg, S. A., et al, "A Progress Report on the Treatment of 157 Patients with Advanced Cancer using Lymphokine-Activated Killer Cells and Interleukin-2 or High-Dose Interleukin-2 Alone" New Engl.J.Med. 316: 898, 1987; and Lotze, M. T., et al, "High-Dose Recombinant Interleukin-2 in the Treatment of Patients With Disseminated Cancer" J.A.M.A. 256: 117, 1986.
In addition, systemic therapy is made more difficult by the fact that cytokins are rapidly eliminated from the blood. For example, interleukin-2 has a half-life in the blood of 13 minutes. A further problem is that the blood contains powerful cytokin inhibitors. (See Kucharz, E. J., et al. "Serum Inhibitors of Interleukin-2" Life Sci. 42: 1485, 1988).
Local administration of cytokins leads to far fewer side effects. In this regard see Forni G., et al. "Tumor Immunotherapy by Local Injection of Interleukin-2 and Non-Reactive Lymphocytes", Prog. Exp. Tumor Res. 32: 187, 1988; Gramatzki, M. et al, "Intralymphatic Interleukin-2 Treatment in Patients with Acquired Immunodeficiency Syndrome: Preliminary Experience in Three Cases" Immunobiol. 172: 438, 1986; Bubenik, J. "Local immunotherapy of cancer with interleukin-2", Immunol. Let. 21: 267, 1989; Lotze, M. T., et al. "Intraperitoneal Administration of Interleukin-2 in Patients with Cancer" Arch. Surg. 121: 1373, 1986; Yasumoto, K., et al. "Induction of Lymphokine-activated Killer Cells by Intrapleural Installations of Recombinant Interleukin-2 in Patients with Malignant Pleurisy Due to Lung Cancer" Cancer Res. 47: 2184, 1987. However at present no use is made thereof, because there is almost always a systemic disease at hand, such as metastasized tumor, generalized immune deficiency (AIDS) and autoimmune diseases and adequate immuno-stimulation is not brought about through a short term, local application. The technically complicated, expensive and patient-stressing method of adoptive infusion of immune cells has been employed as a way out. In this regard see Rosenberg, S. A. "Immunotherapy of Cancer by Systemic Administration of Lymphoid Cells Plus Interleukin-2", J. Biol. Resp Mod 3: 501, 1984; Mittelman, A., et al, "Treatment of Patients with Advanced Cancer Using Multiple Long-Term Cultured Lymphokine-Activated Killer (LAK) Cell Infusions and Recombinant Human Interleukin-2", J Biol Resp. Mod. 8: 468, 1989; Rosenberg, S. A. "Lymphokine-Activated Killer Cells: A New Approach to Immunotherapy of Cancer", J.N.C.I. 75: 595, 1985; Paciucci, P. A., et al, "Recombinant Interleukin-2 by Continuous Infusion and Adoptive Transfer of Recombinant Interleukin-2-Activated Cells in Patients with Advanced Cancer", J. Clin. Oncol. 7: 869, 1989; Grimm, E. A., et al, "Lymphokine-Activated Killer Cell Phenomenon", J. Exp. Med. 155: 1823, 1982; Rosenberg, S. A. "Observations on the Systemic Administration of Autologous Lymphokine-Activated Killer Cells and Recombinant Interleukin-2 To Patients with Metastatic Cancer", N.Engl.J.Med. 313: 1485, 1985; Belldegrun, A., "Lymphokines and activated cells in experimental and clinical immunotherapy" In: Immunotherapy of Urological Tumors (ed. deKernion JB), Churchill-Livingston 1990.
Endogenic immune cells have been taken from the patient (cf. FIG. 24.1 in Belldegrun, ibid.), which are either cells from the blood, which are non-specifically stimulatable, or immune cells are directly obtained from the tumor, i.e. from the diseased or affected area, which are specifically stimulatable against antigens.
These immune cells are then mixed with corresponding cytokins in vitro, i.e. in the test tube and are replaced after successful stimulation. This involves considerable effort and expenditure, above-average quantities of equipment and specially trained staff (cf. FIG. 24.2 in Belldegrun, ibid.).
The taking of these immune cells involves an infection risk for the patient. The re-infusion can also represent an infection source for the patient (hepatitis transmission has been reported). As the cells are firstly taken from the patient and then stimulated in vitro, in the case of repeated therapy cycles, intervals occur between the individual therapies, which is not desired with such diseases. For these and other reasons, the aforementioned application cannot be used as a long-term process lasting months or even years. However, a long-term application is the prerequisite for effective immunotherapy.
The problem which the invention seeks to solve is to develop a cytokin application, which can continuously extend over a long period, i.e. months to years, which has few side effects and which still has a powerful systemic action. Application must be simple and rapidly performable for the patient, without requiring equipment or processes which are complicated with regard to technology and personnel.
According to the invention this problem is surprisingly solved by the use of cytokin-containing aerosols for inhalative application and immuno-activation or continuous immuno-regulation in tumor diseases or the use of cytokin-containing substances for producing an aerosol medicinal preparation for inhalative application and immuno-activation or continuous immuno-regulation in tumor diseases, and by daily doses between approximately 2 and 5.times.100,000 U BRMP, 2 and 5.times.200,000 U BRMP, 5.times.300,000 U BRMP, particularly 5.times.100,000 U BRMP and 5.times.200,000 U BRMP.
The inhalative application of medicaments is not novel per se. However, this has hitherto involved the use of other medicaments and with completely different aims, e.g. asthma patients or allergic persons e.g. inhale substances during an acute pulmonary disease, e.g. for expectoration purposes. In the case of AIDS patients, antibiotics are applied by inhalation, to avoid local infection risks.
However, the inventive concept of obtaining a systemic action, in that the large local surface of approximately 100m.sup.2 of the lung is utilized in order to activate immune cells reachable on this surface, and to make the same available to the circulatory system, satisfies a longstanding need for achieving very high tumor regression throughout the body by simple application or administration.
Equally novel and characteristic for the inventive use of cytokin-containing aerosols is the advantageous use over many months and daily application for many days. This combination induces an optimum, continuous immuno-stimulation, which cannot be achieved as efficiently and without side effects in any other way. The effectiveness can not only be measured through the regression of metastases, but also on the cytotoxicity of the stimulated cells.
The analysis of the inventively obtained cytotoxicity shows a clearly increased tumor toxicity of the immune cells present in the blood, and also in the phase when the ambulatory patient only receives an inhalative cytokin application and not a systemic application. This high effectiveness and extremely good compatibility could not have been foreseen.
Interleukin-2 systemically brings about a considerable liquid incorporation, so that intravenously treated patients have a considerable risk of a pulmonary edema developing. The inventive application form by aerosol inhalation has not as yet revealed this side effect in patients. A dosage increase has only led to the occurrence of moderate systemic effects (fever, blood pressure reduction, etc.).
Cytokins have been available in unpurified form for decades. For roughly ten years gene-technologically produced and well characterized cytokins have been available.
Although the application form of cytokins has been intensely discussed in smaller and also larger research, cytokin aerosol application has not been as yet considered anywhere in the world. There are two main reasons for this. Firstly, such an impressive systemic immuno-stimulation could not be expected through this local application form and secondly, significant and much more dangerous side effects were expected, namely pulmonary edema, and the induction of lung allergies, etc.
A further possible reason might be that no data was available giving information on the stability and penetrability of cytokins in the form of an aerosol application. Aerosol production equipment has long been known. However, cytokin aerosol application has never been considered.
The inventive inhalative application form with cytokin-containing aerosols has already proved very effective within the scope of a pilot study in the case of patients with incurable carcinomas.
Advantageously the cytokin decisive for immuno-activation, i.e. interleukin-2, is applied to the patient by inhalation as an aerosol several times daily.
The hitherto well accepted doses may vary between 2 and 5.times.100,000 U BRMP and experience exists with dosage increases up to 5.times.300,000 U BRMP/day. Two patients have been treated with this inhalative application for six months and have surprisingly revealed no side effects in the lungs.